Manufacture of electric batteries.



UNITED STATES PATENT QFFICE.

EDWARD BAINES, OF NEW YORK, N. Y.

MANUFACTURE OF ELECTRIC BATTERIES.

SPECIFICATION forming part of Letters Patent No. 636,938, dated November14, 1899.

Application filed une 7,1898. Serial No. 682,861. (No specimens.)

To all whom it may concern.-

Be it known that I, EDWARD BAINES, a sub ject of the Queen. of GreatBritain, residing at New York, (Brooklyn,) in the county of Kings, inthe State of New York, have invented certain new and useful Improvementsin Secondary Electric Batteries and in Methods of Manu facturing theSame, of which the following is a specification.

My invention relates to that class of battery known as the pasted-platebattery.

The object of my invention is to obtain the use of finely-dividedcharcoal, as well as lead oxid, as active material in secondary electricbatteries and to obtain a greater material strength in the negativeelectrode.

We learn from chemistry that charcoal in a finely-divided state has theproperty of absorbing and condensing within its pores many times itsvolume of oxygen.

I obtain the object of my invention in the following manner: I mix leadoxid with sulfuric acid to form a paste, such as is now used insecondary electric batteries, and to this paste I add finely-dividedcharcoal, and this paste of lead oxid, sulfuric acid, and finely-dividedcharcoal I pack into grids, frames, or sup ports of lead, and when it isdry and hard it is ready for use. The active material for the positiveelectrode of my battery is the ordinary spongy lead now in use. Whilethe proportions of lead oxid and finely-divided charcoal may be greatlyvaried without injury to my invention, I find that when I use one ounceof finely-divided charcoal to two pounds of lead oxid I obtain excellentresults. My reason for using charcoal in a finely-divided condition isthat when the battery is being charged it will absorb and condenseoxygen in itsIpores. Charcoal-dust or lump-charcoal is of no use for mypurpose. I next assemble my electrodes in the usual manner of setting upa secondarybattery and immerse them in dilute sulfuric acidsay atwenty-per-cent. solution-and then I pass electric current through thebattery until it is charged.

I do not bind myself to usea positive elec trode of already-formedspongy lead, as the material in the positive electrode may be sulfate oflead, which will be converted into spongy lead by charging anddischarging the battery. The electrodes for my'battery may be formed upseparately, and I prefer this method, as the finely-divided charcoal inmy negative electrode is already-formed active material, and it would bea Waste of time and electric current to act upon it while the ma terialin the positive electrode is being con= verted into spongy lead. It isthe negative electrode of secondary batteries which wears out rapidly;but the negative electrode of my battery is so hard that when I havesubjected one of my batteries to such an intense current of electricitythat the positive electrode is bent into the form of a saucer'mynegative electrode is not in any way injured.

My'battery is specially adapted for use in ships and railroad-cars, as Iuse no packing between the electrodes.

I make no claim to anything new in the manufacture of lead sulfate.Neither do I claim anything new in the supports used in secondarybatteries or in the form thereof; nor do I make any claim to a compoundof charcoal and lead oxid mixed with water or viscous matter or to anycompound of lead oxid and charcoal in a dry state. Neither do I claim,broadly, the use of charcoal or lead sulfate in secondary batteries; nordo I claim the spongy lead in the positive electrode.

What I claim as my invention is In the manufacture of a secondaryelectric battery the method of compounding lead oxid, sulfuric acid andfinely-divided charcoal to wit: first mixing lead oxid and sulfuric acidto form a binder and second incorporating finelydivided charcoal withthis binder substantially as and for the purpose specified.

EDWARD BAINES.

Witnesses:

FRANK G. SMITH, J. L. MORIARTY.

